亚热带城市湖泊与河流CO2气体通量特征及其影响因素

湖泊、河流等内陆水体是连接陆地生态系统和海洋的“长程碳环路”的重要节点,也是温室气体二氧化碳(CO₂)排放源,在调节陆地、海洋间的碳迁移转换中发挥着重要作用。相对于自然水体,城市水体因面积小、水深浅且受监测方法限制,水-气界面碳通量经常被忽略。为探讨我国亚热带城市水体温室气体排放特征,本研究以湖南省长沙市典型城市水体,包括洋湖、西湖、松雅湖、月湖4个湖泊和湘江长沙段为研究对象,分别于2022年4和10月采用光化学反馈-腔增强吸收光谱法(OF-CEAS)和扩散模型法对水-气界面CO₂通量进行对比测定。结果表明,长沙城市湖泊与河流春季为CO₂排放源,秋季为吸收汇,河流水-气界面CO₂通量呈显著季节差异。河湖之间CO₂通量在春季表现为显著差异,秋季差异不显著。CO₂通量与水体溶解氧、水体总氮浓度等呈显著正相关。2种方法的CO₂通量对比测定在湖泊上显著相关,但对河流而言相关性不显著。研究揭示的城市湖泊与河流CO₂气体的排放特征有利于深入探究城市水体碳的迁移转化,可对全面了解全球气候变化过程和河湖湿地温室气体减排和调控提供科学支撑。     

Zur ökonomischen Bedeutung der biologischen Selbstreinigung

In twelve flowing water (Q 1.04… 30.4 m³/s, 0.5… 1.2 m/s) the self-purification efficiency in 110 river sections (L 1.3… 26.4 km) is determined as the load difference in kg · d^?1 COD-Mn as well as in g · m^?3 referred to the daily passage. In the economical comparison, the self-purification efficiency is valued as substitution for wastewater treatment plants of the same capacity. At a mean specific capacity of 8.6 g · m^?3, the self-purification efficiency of the investigated waters is equivalent to economical values of 124 · 10³… 534 · 10³ M km^?1 investment costs, 11 · 10³… 80 · 10³ M · a^?1km^?1 operating costs and 5… 81 MWh · a^?1 km^?1 expenditure of energy. The specific capacity in g · m^?3 COD-Mn shows an exponential regression to the degree of saprobity (L = 0.015 · exp (1.7358 · S)). From this empirical model the limits of the self-purification capacity of aerobic waters by oxygen input can be detected: in respective examples more than 50% of the required oxygen input are due to weirs.     

Studies on Primary Productivity and some Hydrochemical Aspects of a Polluted Water-body of the Himalayan Jhelum Valley

The lake without any outlet (11 ha, 55000 m³, z_max 2,25 m) has a weak thermal stratification with maximum surface temperatures of 32.5 °C. The annual variation of temperature and depth of visibility is unimodal, with the maxima or minima in August. Phytoplankton consists mainly of Cyanophyceae. The primary production determined by the light-dark bottle technique (oxygen method) varies in the annual variation between 0.3… 0.5 g m^?2 d^?1 C (winter) and 3.4… 4.6 g m^?2 d^?1 C (summer); as the annual means of 1975 and 1976 there were found 1.9 and 2.4 g m^?2 d^?1 C, resp., gross production at a utilization of 0.42… 2.85% of the radiation energy. The chemism is a well-buffered hydrogen-carbonate water (pH 8.1… 9.0) with 74… 90 mg/1 Na and 20.5… 31.5 mg/1 K and with a good nutrient supply (20… 40 μg/1 PO₄—P and 100… 240 μg/1 NO₃—N) at the same time.     

Chlorination of Humic Acids and Chloroform Production

By diluting a boggy water there is produced water with a COD-Mn of 3.4 … 10.6 mg/l O₂ which is due only to humic substances. The water is mixed with 2.5 … 12.9 mg/l Cl₂ at pH-values of 5.2 … 8.5 and incubated for 24 h at 20°C. CHCl₃ concentrations of 38 … 480 μg/l were found by the subsequent gas-chromatographic determination. The production of chloroform can be calculated by means of a quadratic polynomial in dependence on COD-Mn, chlorine concentration and pH-value.     

Dissolved oxygen levels in estuarine and coastal waters around Ireland

This paper presents the status of summer oxygen conditions in estuarine and coastal waters around Ireland between 2003 and 2007. Of the 95 water bodies surveyed, 85 had oxygen levels sufficient to support aquatic life. This corresponds to a surface area of 3125 km² or 99.4% of the total area assessed. Ten water bodies, representing a surface area of 20.2 km², were deficient in oxygen but still capable of supporting most aquatic life. No evidence of hypoxia (<2.0 mg/l O₂) or anoxia (<0.2 mg/l O₂) was found. Dissolved oxygen conditions in a number of estuaries continue to improve, probably due to improved municipal waste water treatment. The implementation of measures contained in both the Nitrates and Urban Waste Water Treatment Directives, together with those of the Water Framework Directive, should ensure areas of oxygen deficiency are eliminated from Irish waters.     

Die gaschromatographische Bestimmung von freien flüchtigen Fettsäuren (C2 — C6) im Sickerwasser von Hausmülldeponien

After extensive experiments aimed at determining the free volatile fatty acids (C₂ to C₆) in organically highly polluted percolation water of household refuse dumping places there proved optimum a column packed with 10% Carbowax 20 M on Chromatron N-AW-DMCS after having been conditioned for five days at 270°C and subsequently covered with 10% hard wax. On short retention times the investigated isomeric column pairs are completely separated. Equally favourable results were obtained also for liquid manure and silage extracts. The detection limits lie between 10 and 20 mg/l, the relative standard deviation is 20 … 30% in the range of the lower detection limit and 2 … 3% at 200 mg/l in the upper range. In the investigation of percolation waters with concentrations between 235 and 4300 mg/l reproducibility lies at a mean relative standard deviation of 0.5 … 2.8%. The technique is well suited for routine checking.     

Verfahren zur Nitrateliminierung im Gewässer

In a storage reservoir with a hypolimnic volume of 3.5 hm³ the water contains 40 mg/l nitrate. A straw bale of 60 by 20 by 1.5 m was introduced as a reactor. Hypolimnic water having been polluted with a waste product of the fatty acid synthesis (30 … 20% formic, acetic, propionic, butyric and valeric acids) were pumped through it. By the use of a total of 43.8 t fatty acid mixture from June to August an additional oxygen depletion of 14 t O₂ is achieved and 49 t NO₃^? are removed at the same time. The ammonium concentration did not increase, the NO₂^? concentration, however, rose to 12 … 13 mg/l NO₂ at times. The fatty acids were used up save 0.1 mg/l. The increase of the NO₂^? concentration, of the number of germs and of the iron, manganese and phosphorus back solution due to the controlled anaerobic conditions is the drawback of the process.     

湖库温跃层溶解氧最小值的形成原因、衍生的生态风险及控制研究进展

溶解氧（DO）对湖库的生物地球化学循环、生态系统结构和功能起着至关重要的作用,也是评价水生态系统的敏感性指标.DO浓度的降低对水生态有着重要影响.结果显示,多数湖库在夏秋季热分层期间,由于温跃层较高的密度梯度、藻类衰亡和有机质的降解以及微生物的呼吸作用会消耗大量的DO,从而形成温跃层溶解氧最小值（MOM）,甚至在该区域诱发厌氧状态.MOM可驱动浮游动物日夜垂向迁移,影响无脊椎动物和鱼类分布迁移模式及种群结构,破坏水体生态分布,致使生物非正常死亡,危害水体生态安全;此外,MOM也可诱发温跃层温室气体（CH₄和CO₂）大量形成,影响水源地水质,成为湖库生态安全隐患.目前对MOM所导致的生态风险和水质问题以及最终的控制方法已有较多研究成果,但缺乏综述性的研究.本文从MOM研究历史、研究方法、形成原因、生态风险及控制方法等方面进行论述,并展望今后研究热点,旨在推进MOM的相关研究进展,保障湖库生态平衡和供水水质安全.     

Methanogenesis and organic matter destruction in bottom sediments of technogenic water bodies

Traits have been revealed in the microbial processes of methane formation and organic matter destruction in bottom sediments of technogenic water bodies, in which at the abundance of C_org compounds, including toxic, dissolved oxygen deficiency, and low redox potential, organic matter decay in sediments is mostly anaerobic with the predominance of methanogenesis and sulfate reduction. Data on major microbial processes are used to calculate the total sludge destruction; it is maximal in the sediments of low-toxicity technogenic water bodies; organic matter destruction in them is mostly due to methanogenesis; it is minimal in high-toxicity water bodies, the share of sulfate reduction in them increases, and that of methanogenesis decreases.     

Nitrogen compounds in the surface and subsurface waters of Karelia

Materials of long-term studies of the concentration and distribution of N forms (NH₄⁺, NO₃⁻, NO₂⁻, N_org) in precipitation, surface water and groundwater are generalized. Precipitation was found to be the main source of N compounds input into these waters. The effect of anthropogenic factors is local and does not influence the concentration and distribution of N forms in most water bodies that serve as wastewater recipients. The N forms dominating in precipitation are NO₃⁻ and N H₄⁺; N_org dominates in most surface water bodies, and NO₃⁻ dominates in groundwater. The median concentrations of N_tot in clear surface and subsurface waters are similar. The obtained characteristics of the concentrations and distribution of N forms in natural waters of Karelia can be used for other water bodies in the humid zone.     

Short Term Effects of Aldrin and Swascofix CD-38 on the Feeding and Respiratory Behaviours of Clarias batrachus and Cirrhina mrigala

Fish were kept in non-toxic water or at 0.5, 0.25 and 0.125 of the LC_50,96h of the ten-side or insecticide for 24 h and fed with toxified and non-toxified feed. Toxified feed in normal water resulted in a maximum feed intake, while normal feed in toxified water resulted in a minimum one. In each case, the feed intake was lower compared with the control, and the feed intake was inversely proportional to the toxicant concentration. In a simple respirometer the oxygen consumption in mg · kg^?1 · h^?1 was tested for 1, 2, 4, 6, 8, 10, 12, 24, 36, 48, 60, 72, 84 and 96 h of exposure to 1.5, 1.0 and 0.5 of the LC_50,96h of both substances. It was a flow device which was closed only for measurement for one hour. 1.5 LC₅₀ Aldrin causes a continuous reduction of respiration until death. The same effect occurred with Cl. batrachus for 1.5 LC₅₀ of the tenside, whereas with C. mrigala death was caused by a pronounced increase of respiration. In all other cases, after a phase of sensitization for 4 … 8 h respiration increased considerably to more than 300% of the control, which was followed after 12 … 24 h by acclimatization to normal respiration values.     

Daphnia magna as a Model to Assess Heavy Metal Toxicity: Comparative Assessment with Mouse System

The acute static bioassays with heavy metals at 13 ± 1.5 °C in hard water (total hardness = 240 ppm as CaCO₃) were conducted in the laboratory with Daphnia magna. The 48 hr LC values and their 95 per dent confidence limits in ppm of metal were: 0.0038 (0.0027… 0.0053) for Hg; 0.015 (0.009… 0.026) for Ag; 0.1 (0.063… 0.16) for Cu; 0.69 (0.48… 1.0) for Zn; 1.52 (1.01… 2.28) for Co; 1.8 (1.16… 2.70) for Cr; 1.5 (1.07… 2.1) for Cd; 2,63 (1.7… 4.08) for Pb; 7.3 (5.49… 9.71) for Ni and 19.5 (13.45… 28.3) for Sn. At the close of 24 h of exposure Zn and Cd solutions showed milky white precipitation. The order of toxicity of heavy metals in this model was: Hg>Ag>Cu>Zn>Cd>Co>Cr>Pb>Ni>Sn. Comparison of D. magna and mouse LC₅₀ data showed that Daphnia were sensitive at 1/2710, 1/83, 1/123 and 1/5.5, the LC₅₀ values of Hg, Cu and Zn, respectively. Toxicity test with D. magna is simple, requiring less space, time, facilities, acclimatization time and equipment. Furthermore, Daphnia is more functional, reliable and gives reproducible results. Based on this data we believe the Daphnia magna model can be used as a model to study heavy metal toxicity.     

Modelling spatial variations in dissolved oxygen in fine‐grained streams under uncertainty

This paper presents a novel triple‐layer model, called VART DO‐3L, for simulation of spatial variations in dissolved oxygen (DO) in fine‐grained streams, characterized by a fluid mud (fluff or flocculent) layer (an advection‐dominated storage zone) as the interface between overlying stream water and relatively consolidated streambed sediment (a diffusion‐dominated storage zone). A global sensitivity analysis is conducted to investigate the sensitivity of VART DO‐3L model input parameters. Results of the sensitivity analysis indicate that the most sensitive parameter is the relative size of the advection‐dominated storage zones (A_s/A), followed by a lumped reaction term (R) for the flocculent layer, biological reaction rate (μ_o) in diffusive layer and biochemical oxygen demand concentration (L) in water column. In order to address uncertainty in model input parameters, Monte Carlo simulations are performed to sample parameter values and to produce various parameter combinations or cases. The VART DO‐3L model is applied to the Lower Amite River in Louisiana, USA, to simulate vertical and longitudinal variations in DO under the cases. In terms of longitudinal variation, the DO level decreases from 7.9 mg l at the Denham Springs station to about 2.89 mg l^?1 at the Port Vincent station. In terms of vertical variation, the DO level drops rapidly from the overlying water column to the advection‐dominated storage zone and further to the diffusive layer. The DO level (C_F) in the advective layer (flocculent layer) can reach as high as 40% of DO concentration (C) in the water column. The VART DO‐3L model may be applied to similar rivers for simulation of spatial variations in DO level. Copyright © 2014 John Wiley & Sons, Ltd.     

Studies on the Pollution of the Kalinadi by Industrial Wastes Near Mansurpur Part 1: Hydrometric and Physico-Chemical Characteristics of the Wastes and River Water

Stream pollution by industrial wastes is posing a problem in Uttar Pradesh. In the present investigations an attempt has been made to study the ecological features of a section of the Kalinadi so as to find out the cumulative or detrimental effect of pollution on fish and fisheries by the effluent discharge of sugar factory and distillery wastes near Mansurpur (District Muzaffarnagar), U. P. This paper is part I of the project. The liquid wastes produced by the sugar factory vary from 66 × 10⁶ to 88 × 10⁶ litres/day excluding condenser water and contain variable quantities of cane fibres, cellulose, lime, waxes, fermented sugar juice, mollasses, and some quantities of sulphate, phosphate, and nitrogen, the oxygen being nil with high values of B. O. D. and C. O. D. The liquid waste from the distillery is called spent wash. The spent wash (62 × 10⁴ litres/day) is highly coloured and acidic (pH 4.3 … 2.9). The B. O. D. and C. O. D. values were very high in the order of 28,526 mg/1 … 45,146 mg/1 and 52,516 mg/1 to 66,862 mg/1. Thus total waste of about 17.3 × 10⁶ litres with no oxygen and high B. O. D. (9,600 mg/1 … 10,116 mg/1) is let off into the Kalinadi. Hydrometric observations on the Kalinadi show that the pollutional hazard is appreciable during the low flow period of the river. The wastes affect the river in a number of ways:

• - The deposition of cellulose fibres, organic and inorganic matter affects the substratum adversely. The blackish brown colour of the wastes affects the light penetration by limiting the growth of phytoplankton.
• - There appears to be no potential danger to the river from the electrolyte pollution as the specific conductivity lies below limiting values.
• - Changes in pH in river water due to the acidic nature of the wastes do not affect directly the fauna and flora, but the acidic condition becomes lethal in the presence of low oxygen and high temperature values.
• - The high load of organic matter present in the wastes draws heavily on the oxygen budget of the river and adversely changes the water and bottom quality of the river for a stretch of 10 km, which adversely affects the environmental condition of both fish and fish food.
• - The presence of sulphuric acid in distillery waste and hydrogen sulphide in river water is toxic to fish and fish food.
• - The decomposition of organic matter in an anaerobic condition and in another favourable environment, as with a low redox potential, the presence of sufficient organic matter and a constant supply of sulphur-reducing bacteria, produces more hydrogen sulphide which may be detrimental or sublethal in the presence of a low oxygen saturation and high temperature.
• - The oxygen level increases at each succeeding station through reaeration and dilution with the lowering of B. O. D. and C. O. D. The oxygen-sag curve is like a typical spoon with handle-shape.

     

Der Einfluß von Erdölkohlenwasserstoffen auf die Primärproduktion des Donauplanktons

Danube river water samples were saturated with mineral oil, and then the primary production (gross) was determined by means of the light-dark bottle method (oxygen) in situ at depths of 0.1… 1.5 m in comparison with untreated samples. Samples were exposed for half a solar day alternately during the first and second half-days. Investigations carried out between March and October for periods of 14 days showed a mean production of 2.56 g · m^?2d^?1 O₂, which was reduced by 36% due to 12.6 mg/l hydrocarbons. Production decreases with the water depth from 6.2 to 0.9 mg · l^?1d^?1 0₂, whereas the inhibition by hydrocarbons increases from 31 to 41%.     

Hydrobiological Investigations of the Water Quality of the Water Supply Reservoirs Husinec and Římov

The two eutrophicated reservoirs Husinec (2.6 km³, 35 ha, z_max 18 m, MQ 1.87 m^3/s) and ?ímov (34.5 hm³, 216 ha, z_max 44 m, MQ 4.14 m^3/s) show concentrations of total phosphorus of 10… 50 mg/m³ and chlorophyll contents of 7… 36 mg/m³ in the summer season. For both reservoirs a good correlation exists between the chlorophyll concentration and the density of the phytoplankton (20 · 10³… 13 · 10⁶ ind./l). With average concentrations of 10… 20 mg/m³ chlorophyll a in summer, the water can be treated for producing drinking water only at a higher expenditure. The water quality will be improved by a reduction of the phosphorus load.     

Stabilization System for Waste Water Treatment and Use. Part 1. Chemistry

The difficulties arisen in an assimilation pond, as it is called, after 17 years of operation were solved by a stabilization system for the purification of effluents and utilization for fish breeding. It consists of two basins (0.56 and 1.04 ha) and a fish pond (15.58 ha) to which water can flow from a brook by-passing the system. When the stabilization system had worked for 6 years, it was proved that in the case of the average daily intake of milk of 93,846…118,134 litres, effluents flowing out of the dairy plant amounted to 205.28…228.53 m³, on average. The BOD₅ of effluents ranged from 201.33 to 261.73 kg/d and the total solids ranged from 95.5 to 139.3 kg/d on average. The average daily outflow from the pond amounted to 394.7…1567.0 m³ of water with 4.1…23.8 kg of BOD₅ and with 29.3…112.4 kg of total solids. The average decrease of the main nutrients and extractable substances ranged from 62.8% (Ca²⁺) to 100% (NO^?3). Only the BOD₅ value at the end of the growing season in 1984 (8.4…10.3 mg/l) exceeded three times the standards for the admissible pollution of the receiving stream.     

Influence of Temperature on the Toxicity of Phenol and its Chloro- and Nitro-derivatives to the Fish Notopterus notopterus (PALLAS)

There is determined the LC₅₀ for 24 … 96 h of phenol, 2,4-dinitrophenol and pentachlorophenol as sodium salt by static assay at water temperatures of 16, 23 and 36°C. In addition, the combinations of the three substances were tested in the same way. With decreasing temperature, the toxicity of the individual substances decreased by 6.5 … 22%, that of the mixtures by 10 … 87%; with rising temperature, the toxicity increased by 38 … 747% and 75 … 744%, respectively. The safety limits at 23°C lie between 0.3 μg/l for a synergistically acting mixture and 0.9 mg/l for an antagonistically acting one; for the individual substances this range is 3.5 μg/l to 0.5 mg/l.     

Phosphorus mass balance in a highly eutrophic semi-enclosed inlet near a big metropolis: A small inlet can contribute towards particulate organic matter production

Terrigenous loading into enclosed water bodies has been blamed for eutrophic conditions marked by massive algal growth and subsequent hypoxia due to decomposition of dead algal cells. This study aims to describe the eutrophication and hypoxia processes in a semi-enclosed water body lying near a big metropolis. Phosphorus mass balance in a small inlet, Ohko Inlet, located at the head of Hiroshima Bay, Japan, was quantified using a numerical model. Dissolved inorganic phosphorous inflow from Kaita Bay next to the inlet was five times higher than that from terrigenous load, which may cause an enhancement of primary production. Therefore, it was concluded that not only the reduction of material load from the land and the suppression of benthic flux are needed, but also reducing the inflow of high phosphorus and oxygen depleted water from Kaita Bay will form a collective alternative measure to remediate the environmental condition of the inlet.     

Phosphorus mass balance in a highly eutrophic semi-enclosed inlet near a big metropolis: a small inlet can contribute towards particulate organic matter production

Terrigenous loading into enclosed water bodies has been blamed for eutrophic conditions marked by massive algal growth and subsequent hypoxia due to decomposition of dead algal cells. This study aims to describe the eutrophication and hypoxia processes in a semi-enclosed water body lying near a big metropolis. Phosphorus mass balance in a small inlet, Ohko Inlet, located at the head of Hiroshima Bay, Japan, was quantified using a numerical model. Dissolved inorganic phosphorous inflow from Kaita Bay next to the inlet was five times higher than that from terrigenous load, which may cause an enhancement of primary production. Therefore, it was concluded that not only the reduction of material load from the land and the suppression of benthic flux are needed, but also reducing the inflow of high phosphorus and oxygen depleted water from Kaita Bay will form a collective alternative measure to remediate the environmental condition of the inlet.